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coresight: tmc-etr: Do not clean trace buffer
authorSuzuki K Poulose <suzuki.poulose@arm.com>
Wed, 11 Jul 2018 19:40:16 +0000 (13:40 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 15 Jul 2018 11:52:56 +0000 (13:52 +0200)
We zero out the entire trace buffer used for ETR before it is enabled,
for helping with debugging. With the addition of scatter-gather mode,
the buffer could be bigger and non-contiguous.

Get rid of this step; if someone wants to debug, they can always add it
as and when needed.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/coresight/coresight-tmc-etr.c

index f88342d..1de05c9 100644 (file)
@@ -13,9 +13,6 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
 {
        u32 axictl, sts;
 
-       /* Zero out the memory to help with debug */
-       memset(drvdata->vaddr, 0, drvdata->size);
-
        CS_UNLOCK(drvdata->base);
 
        /* Wait for TMCSReady bit to be set */
@@ -340,9 +337,8 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
        if (drvdata->mode == CS_MODE_SYSFS) {
                /*
                 * The trace run will continue with the same allocated trace
-                * buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
-                * so we don't have to explicitly clear it. Also, since the
-                * tracer is still enabled drvdata::buf can't be NULL.
+                * buffer. Since the tracer is still enabled drvdata::buf can't
+                * be NULL.
                 */
                tmc_etr_enable_hw(drvdata);
        } else {